If one considers the medicines which are not absorbed by the human system, that is medicines swallowed and evacuated by the digestive tract without entering the blood, their action at various stages of the digestive tract can only take place if this action is not used up by a preceding stage.
In the case of insoluble medication, i.e., absorbents such as activated carbon and simethicone ((trimethylsilyl)-omega-methylpoly [oxydimethylsilylene] mixed with silicon dioxide), are released at the stomach level quickly, with the result that most absorption sites become occupied. Thus, the medication quickly loses its effectiveness before passing into the intestine.
To alleviate these difficulties, manufacturers have provided non-absorbable, gastro-insoluble medications in a package of two dosage forms. One capsule in the package is enterically coated so that the capsule dissolves only in the intestine, while the other capsule dissolves only in the stomach, thus releasing its medication. Carbosilane (a product of the present Assignee, which comprises one enterically-coated capsule of charcoal mixed with simethicone and one non-enterically-coated capsule of the same medication) and Phazym (one enterically-coated capsule of simethicone with one non-enterically-coated capsule of simethicone) are two examples of such medications.
Soluble, non-absorbable, gastro-resistant oral medications are used for treating conditions localized with the gastro-intestinal tract. The medications include some antibiotics, antispasmodics, enzymes, antacids, antimitotics, etc. Unlike insoluble gastrointestinal medications, these substances do not depend on surface area and surface absorbancy for their activity. Accordingly, soluble gastro-resistant oral medications are free of the aforementioned difficulties experienced with gastro-insoluble oral medications. For that reason, those skilled in the art have not considered the possibility of obtaining improved results by providing an enterically coated capsule of a gastro-resistant soluble oral medication with a non-enterically coated capsule of the same medication.
Although gastro-sensitive medications (such as injectable penicillin) and medications which irritate the stomach and may not be used therein have been provided in enterically coated form, no need had been seen for enterically-coated gastrosoluble gastro-resistant medications (i.e., medications which are soluble in and not destroyed by gastric juices) which do not significantly irritate the stomach and which indeed are intended for use therein. Accordingly, a combined dosage form of a gastro-resistant, non-absorbable oral medication in enteric and non-enteric capsules was not previously envisioned.
Yet, as applicants have observed, where a gastro-resistant medicine is soluble, it may be diluted within the stomach before it passes into the intestine. Accordingly, where both the stomach and intestine are to be treated with the same soluble (in the digestive system) gastro-resistant medication, previous medical practice required the administration of a single oral dose, which, upon dilution and use within the stomach, remained at sufficient strength to exhibit useful activity within the intestine. Such large dosages can significantly increase both the occurrence of side-effects and the expense of a medication.